Carabus (Chaetocarabus) intricatus
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Carabus intricatus is distributed in three or four subspecies and their several local variations in mainland Europe from France to Turkey.
The subspecies from more southern Europe are now recognised by some authors as separate species.
The Czech name of the species is wrinkled, which very aptly describes the appearance of the surface of the trunks, which is covered as it were with longitudinal wrinkles, between which several interrupted ribs disappear. Transverse wrinkles also cover the edge of the shield and the forehead between the protruding eyes. The colour of the surface of the beetle body is usually blue to purple with more pronounced margins, very rarely blue-green to green in living specimens.
Very interesting is its rare occurrence in the British Isles, which is so often not officially reported. It was first discovered here in 1811 in the vicinity of the small town of Tavistock in Devon, in the forest site of Double Waters. The site is now a nature reserve in Dartmoor National Park. To this day the beetle is considered a great rarity and the species' range is restricted to a few sites in Devon, Cornwall and Glamorgan. In his book Our Beetles (1963), RNDr. J. Mařan claims that the slipper beetle was introduced individually and artificially to the British Isles by shipping from France. If this was indeed the case, it appears to have acclimatised quite successfully and there is a small but permanent population. Videos and articles can be found on the internet in which local naturalists demonstrate great enthusiasm for local records of the species.
The size of the species in Central Europe very rarely exceeds 35 mm, whereas some of its breeds in the Central Balkans and Greece can boast a body length of over 40 mm, especially notable in females. In the Greek subspecies intricatus krueperi from the Ossa Mountains, this is compounded by a greater width of the trunk than in the nominate race, making the appearance of such a specimen very imposing. Finds of specimens under 25 mm or less are also very rare.
It is rarer in lowland forests and more abundant in forests of the foothills up to the upper forest boundary. I have observed an active imago in the Mala Fatra mountains in Slovakia at Mojžíš springs above Šútovský waterfall at 1100 m.
The most abundant occurrence was in moist deciduous and foothill forests with spruce and fir, where it wintered in the red tinder of fallen coniferous trunks and stumps covered with a thick layer of moss. Click on the mouse to enlarge the following image of such a habitat.
It used to be very abundant in the moist ravines and slopes of these forests in the Oder Mountains in Central Moravia. Under the smouldering bark and deeper in the decayed rotten trunk of a spruce tree I observed dozens of wintering imagas packed close together and under each other in layers like sardines in a can in the pre-spring of 1983. However, such finds are a thing of the past in the Oder Hills, and the beetles are found singly and rarely. Even worse were the so-called protected species Carabus irregularis and Carabus variolosus - these are no longer found in many of their original habitats in the Oder Hills. The blame lies with the drying up of the forests and the artificially induced so-called bark beetle calamity; large sections of natural forest have disappeared, along with conifers and over-aged deciduous stands, and the mega-action 'bark beetle & alleged climate change' has served as an excellent excuse for total clear-cutting of everything that can be quickly monetized. Continuous natural habitats have disappeared, sites and many vernal pools have dried up, and native species have no chance of survival on the dry hard soil of large blown-out strips. Continuous natural habitats have disappeared, sites and many vernal pools have dried up, and native species have no chance of survival on the dry hard soil of large blown-out strips.
Here and there, only truncated islands of forest remain, but these too will fall in the near future for obvious reasons. The species intricatus is probably not in danger of extinction in the Oder Hills area (except for the two species mentioned above!), but the numbers of adult beetles found are very reduced compared to earlier times and the finds are only isolated and accidental.
Species Carabus intricatus was also spreading in large cities from unmaintained suburban forests, which were important refuges for some locally declining species of great crested newts such as C. coriaceus, C. scheidleri and C. ulrichi.
From these habitats, the species intricatus penetrates into gardens and orchards, where in early autumn, together with intrusive wasps, it likes to feast, among other things, on fallen rotting fruit.
Its main food is, however, slugs, earthworms and other small animals that live on the forest floor, including larvae of its own species and other species of mealworms. It is probably always a live food, and carrion is said to be avoided by it, unlike other species of the large swifts of the genus Carabus.
Snails are apparently a frequent and choice delicacy, on whose slimy trail the hungry slippery slipper runs like a dog; on reaching its prey, it buries its long and sharp pincers in the slug's body, which writhes and defends itself by discharging copious slime, but it is of little use to it; the strong beetle does not move, its long legs giving it ample support, and it slowly injects its digestive juices into the slug, the poison of which paralyses the slug's nervous system, so that perhaps a merciful death ensues for it. The slug then simply sucks out the decomposed liquid tissue of its victim.
Sometimes, when observing such a scene, I involuntarily wonder who would be the theoretical prey if the slug grew to a size of around 0.5 m to 1 m.
It can also climb high into the treetops in search of prey, not only C. intricatus, e.g. in southern Bosnia I have observed the Balkan species of C. caelatus dalmatinus individually during night hunting. It seems that species of the genus Carabus, which have very long and strong legs, are better adapted to such acrobatics and also use it successfully to diversify their diet. In the oak forests of the foothills of Slovakia, the species intricatus seems to compete successfully with species of the genus Calosoma in hunting tree caterpillars. Its larvae probably do not possess this ability compared to the larvae of marginals, but rather stick to the ground.
In contrast, the blue Beetle is often a preferred food of larger vertebrates, reptiles and birds, e.g. vipers and vipers, moles, hedgehogs, rays, badgers, foxes, cuckoos, owls, etc.
In the large upper picture is a female of the species, which shows features of the so-called form =angustulus Haury, 1876, according to J. Niedl, 1959 most of the specimens from the Carpathian mountains of Slovakia belong to this form. Similar and slender specimens with narrow racemes are also from southern Slovenia.
Locality Horná Štubňa, central Slovakia, date 30.5.1989, under the protruding bark of a dead and standing stump of a fir tree trunk.
On the picture on the left is a nice illustration
of a slipper species
intricatus from the publication Our Beetles (1963) by RNDr. Josef Mařan, who was a scientist and head of the Entomological Department of the National Museum in Prague, among others a leading expert on the family Carabidae. He made many trips and collected beetles mostly in the Balkans, especially in Bulgaria and Greece.His book was in its time mainly aimed at young people interested in entomology; however, it still has its unmistakable and informative value even after all these years. The texts on some selected species and especially some chapters in the introduction of the book still have something to tell those interested in beetles today. It is currently offered for sale in several antique shops for an inflated and very exorbitant 'trade' price of about 700 to 800 CZK. From the original 20 CZK.
The texts in the book were supplemented with beautiful illustrations by the academic painter František Procházka. His drawing of the wrinkled shoebill is a bit unbelievable as far as the creasing of the trunks is concerned, but beautiful nonetheless.
The author of the interesting text below the picture is Josef Mařan himself.
TRANSLATION: Carabid (Carabus intricatus L.). An interesting species of shoebill that often hunts in trees. In the daytime you can find it under the bark of diseased trees, under wood or flat stones. In the lowlands and mountains, it is abundant in forests, parks and gardens. It is a species that inhabits western and central Europe, the Balkan Peninsula and Italy. In the west, it has reached France as far as Brittany region. But it is a breed which has stunted lower wings, does not fly, and therefore has not crossed the Channel to England. It has indeed been caught several times in England, but it has always proved to be specimens that were introduced into England with goods by shipping. In the Balkans, in the mountains of Greece, at Olympus, Parnassus, and Pindus, lives a beautiful breed of this slipper, whose smurf-blue-coloured trunks and shield are edged with bright red and gold.